New ‘biomarker’ blood test could improve prostate cancer detection

A new DNA-based “biomarker” blood test that complements the currently offered prostate-specific antigen (PSA) test, could greatly improve the accuracy of prostate cancer detection before recommending patients for an invasive biopsy, according to a new study.

University of Cincinnati (UC) researchers conducted a meta-analysis of existing published data related to DNA methylation in bodily fluids. The goal was to evaluate a specific cancer biomarker—known as GSTP1—as a screening tool for prostate cancer.

Lead author of the study and assistant professor of environmental health at the University of Cincinnati, Tianying Wu merged epidemiologic and molecular data from 22 studies conducted in the United States and Europe between 2000 and 2009.

More than 2000 human biologic samples (1,635 prostate cancer cases and 573 controls) were analyzed for the current study, including whole blood, plasma, urine, ejaculates and other secretions.

Wu determined that GSTP1 was a statistically significant biomarker for prostate cancer and could increase the specificity of prostate cancer diagnosis by up to 70 percent as compared to using the PSA test alone.

“The PSA test is highly sensitive, but it cannot differentiate between prostate cancer and benign prostatic conditions such as benign prostatic hyperplasia, leading many men to have unnecessary biopsies,” says Wu.

“Measuring GSTPI in plasma or urine is an easy and non-invasive test. This biomarker will give physicians reassurance regards to whether to conduct biopsies in selected patients,” she added.
The study will be published in the British Journal of Cancer.